The main goal of the proposed research is to advance knowledge of the etiology of anxiety and depression disorders through investigation of risk factors. The particular focus is on developing novel approaches to measuring cognitive vulnerability using innovative analytic methods that better operationalize theoretical formulations and by adapting and extending approaches from experimental and social psychology. Methodological shortcomings are addressed and pragmatic solutions proposed to such problems as the rarity of prospective new cases of disorder, the confounding of severity and chronicity, and the mismatch between theory and operationalization with regard to cognitive diathesis variables. With respect to stress measurement, an ecologically-valid approach is proposed that capitalizes on naturally-occurring events. Finally, methods are specified for applying recent theoretical formulations concerning the self within the social content. Potential vulnerability variables will be evaluated in two nonclinical samples (undergraduates and pregnant women) and a new scale for measuring vulnerability to anxiety will be tested in a clinical sample. In addition, a new approach to exploring the cognitive processes underlying worry will be implemented.